An endangered monkey was brutally beaten and left for dead by his own troop because he could no longer get an erection and satisfy the females.
Cornelius was the leader of 22 other Barbary macaques at Affenwelt - Monkey World - in Sondershausen, Germany.
The 18-year-old ape had been living happily at the large forested terrain of 1.5 hectares exclusively set aside for them, until the shocking case of animal-on-animal violence.
Aging Cornelius had thinning skin, a hump, hardly any teeth left and was impotent, meaning his inability to satisfy the nine female apes had made him a target for his male competitors.
Affenwelt chief Silvio Dietzel said: "As soon as a Barbary male can no longer produce offspring, he is useless for the group.
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"Cornelius is only tolerated, no one has respect for him anymore."
Even when the monkeys are being fed, Cornelius is frequently kicked aside by the other apes.
Mr Dietzel said: "Because his fangs have broken off, he cannot defend himself."
The violence could also be payback time from some of the other apes that Cornelius mauled during his prime.
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Six years ago he incited the entire clan against his rivals resulting in four apes being thrown over a three-meter-high electric fence.
After this zoo chief Dietzel spent two full weeks catching the monkeys and bringing them back into the enclosure.
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Dietzel said: "All the females are at his feet, and that is what counts in the animal kingdom."
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Barbary macaques are found in the wild in Northern Africa and in Gibraltar, and can reach an age of up to 25 years for males and 30 for females.
They are listed as an endangered species.
As well as the Barbary macaques, the Affenwelt Zoo features a handful of other monkey species, some of which like the lemurs are also part of conservation programmes.
